DEEP-SEA NEUTRINO TELESCOPES ANTARES AND KM3NET - MIGUEL ARDID AND MANUEL BOU-CABO
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Deep-Sea Neutrino Telescopes
ANTARES and KM3NeT
Miguel Ardid and Manuel Bou-Cabo
Universitat Politècnica de València, Spain
Outline •Physics with deep under-water (or ice) Neutrino Telescopes •The ANTARES Neutrino Telescope in Mediterranean Sea : – the detector – physics goals – data and first results •The future: KM3NeT •Acoustic activities in underwater neutrino telescopes
Neutrino astronomy
Advantages w.r.t. other messengers (to study the
deepest Universe):
• Photons: interact with CMB and matter
• Protons: interact with CMB and are deflected by
magnetic fields
• Neutrons: are not stable
• Neutrinos point back to the source of emission
• Drawback: large detectors (~GTon) are needed.
photon
n
νµ
p
Point-like cosmic Neutrino Sources
Pulsar Wind Nebulae
Extragalactic
Galactic
Supernova Remnants Microquasars
Active Galactic Nuclei
RX J1713.73946HESS GRB 990123
Their identification requires a detector with
accurate angular reconstruction For transient sources the time meas.
σ (ϑ ) ≤ 0.5° for Eν ≥ 1TeV improves the signal detection
Experimental signal : statistical evidence of an excess
of events coming from the same direction
Diffuse Cosmic Neutrino Sources • Unresolved AGN • Neutrinos from "Z-bursts" • Neutrinos from "GZK like" proton-CMB interactions • Neutrinos foreseen by Top-Down models • …. Their identification out of the more intense background of atmospheric neutrinos (and muons) is possible at very high energies (Eµ > TeV) and implies energy reconstruction.
… not only neutrino astrophysics…
… also open problems in particle physics …
– Dark Matter searches:
• Neutralino annihilation in Sun, Earth, Galactic
Galactic Center
– Monopoles
– Acceleration mechanisms
– Neutrino interaction Cross sections
Neutralino search: χχ → ν+…
– …
Detection principle
Search for neutrino induced events, - Atmospheric neutrino flux ~ Eν-3
mainly νµ N → µ X, deep underwater - Neutrino flux from cosmic sources ~ Eν-2
Search for neutrinos with Eν>1÷10 TeV
Down-going µ from atm. showers
µupgoing / µatm ~ 10-6 at 3500m w.e. depth
- ~TeV muons propagate in water for several km
S/N ~ 10-10 before being stopped
p, nuclei • go deep to reduce down-going atmospheric µ backg.
• long µ tracks allow good angular reconstruction
0.7°
For E ν ≥ 1TeV θ µν ~
E ν [TeV ]
µ direction reconstructed from the arrival time
of Cherenkov photons on the Optical Modules: Cherenkov
Neutrinos from cosmic sources needed good measurement of PMT hits, Neutrino
induce 1-100 muon evts/y σ(t)~1ns, and good knowledge of PMT Telescope
in a km3 Neutrino Telescope positions (σ ~10cm)
p, nuclei
Up-going µ from neutrinos
generated in atm. showers
S/N ~ νastro / νatm ~ 10-4
43°
µ and induced
Cherenkov cone
up-going neutrino Picture from ANTARES
High Energy ν telescopes
Lake Baïkal
Mediterranean
Mediterranean
South Pole
Sky view
North-South common sky : 100 %
0.5 π sr instantaneous Mediterranean
1.5 π sr per day ~ 43o North
Nothern hemisphere detectors : South Pole
Galactic center seen 75% of the time 0%
Cover Hess and Auger skys
Searches for sources…
VHE γ-ray sources (107) detected by Cerenkov telescope
Galactic plane (61)
→ Many sources without counterpart (unidentified)ANTARES Collaboration
NIKHEF, University of Erlangen
Amsterdam Bamberg Observatory ITEP,Moscow
Moscow State Univ
Utrecht
KVI Groningen
NIOZ Texel
ISS, Bucarest
IFIC, Valencia
UPV, Valencia
UPC, Barcelona
CPPM, Marseille
DSM/IRFU/CEA, Saclay
APC, Paris University/INFN of Bari
University/INFN of Bologna
LPC, Clermont-Ferrand 7 countries
IPHC (IReS), Strasbourg University/INFN of Catania
29 institutes
Univ. de H.-A., Mulhouse LNS – Catania
University/INFN of Pisa
~150 scientists+engineers
IFREMER, Toulon/Brest
C.O.M. Marseille University/INFN of Rome
LAM, Marseille University/INFN of Genova
GeoAzur Villefranche ANTARES site is about 2475 m deep
and 40 km from Toulon (France)The ANTARES experiment
• String-based detector;
• Underwater connections by deep-sea submersible;
• Downward-looking PMTs, axis at 45º to vertical;
• 2475 m deep.
14.5m
Horizontal layout
25 storeys,
348 m
•40 km
•cable to
•shore
100 m
Junction Box
• 12 detection lines
• 25 storeys / line
~70 m • 3 PMTs / storey
• 885 PMTs
“ANTARES: The first undersea neutrino telescope”, NIM A 656 (2011) 11-38.Storey: Basic detector element
Optical
Beacon
for timing
calibration
(blue LEDs)
1/4 floors
Optical Module in
17” glass sphere
Hydrophone RX
Local Control Module
(in the Ti-cylinder)Expected Performances (full detector)
Neutrino effective area Angular resolution
• For Eν10 PeV the Earth becomes opaque track reconstruction uncertainties.
to neutrinos.Reconstructing the muon track direction: a χ2 strategy
Track reconstruction based on χ2 fit of the photon arrival times on fired PMTs
Multi-line track fit of
θ
tracks reconstructed horizon
as upward-going
2008 data
downward-going MC
atmospheric muons
hor.
up-going MC
atmospheric up down
neutrinos
Elevation angle distribution for events with Q5 lines (2007): Depth Intensity Relation
2,5km
6km
Zenith angle distribution of
I(θ = 0,h) = I(θ,h0 ) ⋅ cosθ ⋅ c corr (θ )
muon flux at 2000m depth
N(θ,h0 ) ⋅ µ(θ,h0 )
I(θ,h0 ) =
Aeff (θ,h0 ) ⋅ T ⋅ ∆Ω
h=h0/cosθ slant depth
N(θ,h0) # of muons in angular bin
µ(θ,h0) mean bundle multiplicity
ccorr (θ) Earth curvature correction
D.I.R. parametrization from:
E.V. Bugaev et al., Phys. Rev. D 58 (1998) 05401.
Reconstructed track rate=1.52Hz
“Zenith distribution and flux of atmospheric muons
measured with the 5-line ANTARES detector”,
Astroparticle Physics 34 (2010) 179-184Coincidences between adjacent storeys (low E atm. muons)
Analysis performed on 5-line detector data
Energy threshold
~ 4 GeV muons
Data/MC ratio ≈ 1.1 optical noise from 40K decay
• Data: low-background (Event rate as a function of floor depth
By repeating the analysis for every detector storey the effect of muon flux
reduction with depth is directly measured
After corrections for the presence
of dead channels and uneven
efficiencies of the OMs, as
measured with 40K, the fluctuations
of data points are compatible with
statistical errors
Φ(h) = Φ 0e(h0 −h )/ λ
Systematic errors mainly in
normalization (+50/-35%),
otherwise ~3%
+0.63
“Measurement of the atmospheric muon flux with a 4 GeV Φ 0 = 1.18 ± 0.01(stat)−0.39 (syst) ⋅10−3 m−2 s−1
Threshold in the ANTARES neutrino telescope”
Astroparticle Physics 33 (2010) 86-90 at h0 = 2200m with λ = 540 ± 25m2007 and 2008 data analysis: νµ from point sources
Selected up-going reconstructed tracks
From MC: angular error estimate < 1°
Λ>-5.4: selected
2040 events
Look for
zenith
neutrinos
into the
"up-going
horizon tracks”.
• Reconstruction algorithm (max. Likelihood The selected sample of tracks dominated by
strategy) optimized to reach angular up-going atmospheric νµ and mis-reconstructed
resolution ≤0.2° for Eµ> TeV and to down-going muons.
reduce the atmospheric muon background The Λ quality cut enhances the νµ component
in the up-going reconstructed tracks sample.
• Blinding policy followedANTARES: search for point like sources
Search for point-like sources at their
known location
ANTARES 2007+2008
preliminary
Skymap Galactic
Coordinates
2040 up-going νµ ANTARES: flux limits on 24 candidate point
sources and sensitivity (median expected limit)ANTARES: search for point like sources
Search for point-like sources at their
known location
ANTARES 2007+2008
preliminary
Skymap Galactic
Coordinates
2040 up-going νµ ANTARES: flux limits on 24 candidate point
sources and sensitivity (median expected limit)ANTARES: search for a flux of “diffuse νµ”
Selection criteria
First level: good quality upgoing tracks. reconstructed
as down-going
Second level: Λ vs Nhit
Energy estimator:
Repetition (R) of integration gate on the
same Optical Module Atm µ wrongly
reconstructed +
upgoing neutrinos
R vs Energy
Optimization by
Model Rejection factor
Distribution of the R parameter for the 134 neutrino
candidates in the 334 days of equivalent live time
22ANTARES: search for a flux of “diffuse νµ”: results
E2Φ(E)90%= 5.3×10-8 GeV cm-2 s-1 sr-1
20 TeVANTARES: indirect search for Dark Matter
Search for neutrinos from dark matter annihilations in the Sun
χ Sun
WIMPs gravitationally trapped Earth
via elastic collisions in the sun
χ χ
χ χ ν
χ
χ χ → WW, ff ANTARES
W, f → νX ~ Mχ/3
Upper limit on the neutrino Upper limit on the total
flux from the Sun
Ф(νµ+νµ) from neutralino
arXiv:0905.2316v3 annihilations in the Sun as
function of mχ
mSugra model predictions
• green : WMAP favoured relic density
• red : > WMAP favoured relic density 5 Line Detector
• blue : < WMAP favoured relic density Feb - Dec 2007
168 active days
24A multi-messenger approach: “GRB trigger”
GCN alerts trigger the recording of all the low
level triggers. A continuous buffer ensures
the availability of the data before the alert
t =-250 s GCN=Gamma Ray Burst
Coordination Network
t = 0 s
Data taking triggered by a satellite (FERMI; SWIFT, INTEGRAL)
t = 20 s
All data is written to disk
t = 200 s
Specific data filtering and reconstruction by searching
for an excess of events in the GRB direction (offline)
t = 1 h
25“GRB triggered” data analysis
ANTARES time response to a satellite alert message
Cumulative numberb of alerts black:
GRB alerts received Response time = t early _ hit − t trigger
ANTARES satellite
flaring activity of red:
SGR 1550-5418 the ones Antares
triggered on
most of GRB alerts
90% Upper limits on ν fluxes form 37 GRBs
by the Swift satellite
GRB alerts also from
the Fermi satellite
Time (date)
• > 1300 alerts from GCN have been recorded
(Jan 2011)
Expected ν fluence for 37 GRB
• The analysis of Lines 1-5 data is going on: with W&B energy spectrum
the time period contains 37 GRB alerts.
• The total prompt emission duration of the 37 Expected ν fluence for 37
GRB according to Guetta
GRBs is 1882 s et al.
26Multi-messenger approach
ANTARES alert
• Two events with
Agreement with TAROT ΔΩ < 3⁰ x 3⁰
Telescopes à Action Rapide pour l’Observation de Transients)
Δt < 15 min
• TAROT: two 25 cm telescopes at Calern
Rate(atm) = 0.05 yr-1
(France) and La Silla (Chile)
• High Energy ν event
• FOV 1.86⁰ x 1.86⁰
Rate ~ 2 per month
• ~10 s repositioning after alert reception
•Operational since beginning of 2009: > 20 alerts
have been sent to the robotic telescopes.
•MoU has been signed with Tarot, a second MoU is
in discussion with ROTSE, whose 4 telescopes
receive the Antares alerts since 1 year.
•A paper on the performances of the alert system
Priorities (decreasing with time) are set to alerts. submitted to Astroparticle Phys.
SWIFT has the highest priorityMulti-messenger approach
Gravitational Waves and Neutrinos
• Possible common sources
(GRB-core collapse into BH; SGR – powerful
magnetars; hidden sources)
• Sky regions in common
• Expected low signals, coincidences increase
chances of detection
• GW & HEN is a mustEarth-Sea Science
• Continuous monitoring of oceanographic
instrumentation:
– Correlation between different parameters: sea currents,
salinity, temperature, bioluminiscence, count rates, etc...
– Bring some light in complex multidisciplinary problems
“Acoustic and optical variations during rapid downward motion episodes in the deep
north-western Mediterranean Sea”
Deep Sea Research I 58 (2011) 875-884.Earth-Sea Science
Seismograph
In laboratory 40
20
0
-20
-40
Deployment
Buried at siteThe Neutrino Telescope World Map ANTARES + NEMO + NESTOR joined their efforts to prepare a km3-scale Cherenkov neutrino telescope in the Mediterranean KM3NeT Consortium
KM3NeT
• KM3NeT consortium is formed by (40) European institutes or university
groups from the following ten countries: Cyprus(1), France(6), Germany(2),
Greece(5), Ireland(1), Italy(12), Netherlands(5), Romania(1), Spain(3), UK(4)
• KM3NeT, an European deep-sea research infrastructure (included in the
ESFRI list), will host a neutrino telescope with a volume of several cubic
kilometres at the bottom of the Mediterranean Sea.
• The facility will also house instrumentation from Earth and marine sciences
for long term and on-line monitoring of the deep sea environment.
• Design Study and Preparatory Phase funded by the EU Framework Programs.
now
Design Study
Preparatory Phase
KM3NeT
Prototyping/construction
Data TakingThe KM3Net Detector Digital Optical Module (DOM) floors Detection Units (DU) Compact Deployment
Detector configuration
• 320 DUs @ 180 m
• 20 floors @ 40 m / DU
– Active height = 760 m
• 2 DOMs / floor
• 31 PMTs/DOMs
• Hexagonal sea floor layout
• ∼ 50 DUs → 1 km3 instrumented volume
• Total Estimated Cost: 200 M€
• Pre-Production Model of the DU being built. To be deployed and tested in 2012Single Site or Distributed Sites
Antares (1/50 km3)
Toulon, France
-2475 m
Nestor
Pylos, Greece
Nemo -3000 m to -5200 m
Capo Passero, Italy
-3500 mSummary • ANTARES is the largest neutrino telescope in the Northern hemisphere, the first one at deep-sea • Full volume (12-detection lines) reached in May 2008 • Detector is well working, within design specifications – Technical challenge successfully realized – Maintenance in deep sea is possible – Data collection ongoing – Long-term investment in software framework and procedures – Data analysis ongoing, first results published • Multidisciplinary platform for associated sea sciences • Milestone towards the km3 underwater neutrino telescope • KM3NeT is progressing, and now in a critical phase: – Pre-Production Model to validate the technology – Set the legal entity and clarify the funding
Acoustics for underwater neutrino telescopes
Miquel Ardid and Manuel BouAcoustic Activities Acoustic positioning system Acoustic detection of neutrinos
Acoustic positioning system (Intro).
/
=
3D PMT array /
2
Cherenkov light from µ
γ
Measurement :
Time, position &
µ amplitude of hits
2500 m depth
43° Interaction
ν µ (~ ν) trajectory
&
energy
39Acoustic positioning system (Intro).
APS must provide the position of :
- Mechanical structures, in a geo-referenced
coordinate system, with an accuracy of
about 1 m.
- The positions of OMs in deep sea, with an
accuracy of about 10 cm.
APS is composed by three main items:
- (LBL) set of acoustic transceivers.
- An array of acoustic receivers (hydrophones)
rigidly attached to the telescope mechanical
structures.
- An onshore PC farm to analize the APS data
analysis, on-shore.
Detail of acoustic positioning system
operation in ANTARES
40Acoustic positioning system (Antares).
- Thorough its construction Antares telescope has passed through different number of lines and configuration.
APS was extensevely studied
Left The horizontal movements from BSS, of all hydrophones on Line 11 for a 6 month
period
Right-The difference between the X-position of storey 14 on Line 1 calculated by the
hydrophone data and the X-position obtained by the line fit.
The accuracy nedeed has been achieved
41Acoustic positioning system (KM3NeT).
- During last years Gandia`s group is involved in R & D for the acoustic positioning system for KM3NeT in
collaboration with the INFN (Istituto Nazionale di Fisica Nucleare) and CPPM (Centre de Physique des
Particules de Marseille).
- Long Base Line Acoustic Positioning system for KM3NeT consists of a series of acoustic transceivers
distributed on the sea bottom. Each of these acoustic transceivers is composed of a transducer and the
associated electronics.
Emitter transducers.
LBL designed is composed by
Sound emission board.
Transducers specifications: Electronic board specifications
- Reasonable power level. - Power consumption < 1W at 5V & 12V.
- Convenient resonance frequency. - RS232 Communication Port .
- Capacity of work at high depth. - Times sinchronization with an accuracy
around 1µs.
- Good directivity (omnidirectional desired)
- It might work in emission and reception
mode.
42Acoustic positioning system (Hydrophones).
- Efficient transducer, that
provides reasonable power of
level.
- Have “unlimited” depth for
operation (has been tested up
to 440bars).
- Omnidirectional directivity
pattern.
Free Flooded Ring (FFR) sensors, model
SX30 manufactured by Sensor - Transmitting voltage response :
Technology Ltd 133 dB Ref. 1μPa/V at 1m
- Receiving Voltage response
4.4 cm -193 dB Ref. 1V/μPa,
2.5 cm
2 cm - The maximum input power is 300 W
with 2% duty cycle.
- 20–40 kHz frequency range.
43Acoustic positioning system (Hydrophones).
Hydrohones have been tested in lab and under high pressure conditions.
Hyperbaric tank at IFREMER
research facilities, PLOUZANE
(near Brest - France )
44Acoustic positioning system (Hydrophones).
Some little variations in the
relative acoustic power with
the pressure in the [24-40]
kHz frequency range. In
addition, no
significant drifts on time
were observed
Example of results obtained in relation with pressure test
45Acoustic positioning system (SEB).
- Sound Emission Board has been developed at IGIC-UPV Gandia. It is specially adapted to the FFR
transducers and is able to feed the transducer with high amplitude short signals (a few ms) with arbitrary
waveform.
Board specifications
- Use the power supply granted by the telescope.
1 W approx
- It must have a low speed port for configuration
(RS232,RS485…)
- The board have to emit the signal when it
detect a LVDS trigger signal. The accuracy in the
emitting delay must be less than 1µS.
- The system life expectancy must be more than
twenty years.
46Acoustic positioning system (SEB + HYD).
- Tests have been done in the laboratory of the IGIC-UPV in Gandia in the week the 5-12 May
2010 together with INFN INFN-Italy, CPPM-France and ECAP -Germany.
- Goal of the test was to prove compatibility and functionality of different hardware and software
developed within KM3Net for an innovative acoustic positioning system
47Acoustic positioning system (SEB + HYD).
- Latency time of the full system.
48Acoustic positioning system (SEB + HYD).
Developed system is currently integrated in IL11
of Antares (will be connected in a few weeks).
In addition a SEB + FFR is under integration
process in the framework Nemo Phase 2.
Detail of SEB integrated inside of titanium
vessel (Laser calibrator developed by IFIC
team ).
49Acoustic detection neutrinos (Intro)
G.A.Askaryan. Hydrodynamical emission of tracks of
ionising particles in stable liquids. J. At. Energy 3 (1957) 921.
Temperature
d2 Time
dt2
h
∝
∆t
When a UHE neutrino interacts with the matter, the energy is deposited fast and locally. A
thermo-acoustic pulse is generated and propagates perpendicularly to the direction of the
hadronic shower produced.
The acoustic signal has a bipolar shape in time and a 'pancake‘ directivity
50Acoustic neutrino detection (AMADEUS)
Transients from mammals
- Total of six acoustic storeys.
- Three on the Instrumentation Line (IL07).
- Three on the 12th detection line (L12).
- 34 sensors fully operationally. .
Studies performed.
- Long term background investigations.
- Investigation of spatial correlations for transient signals and for
persistent background on different length scales
- Development and tests of data filter and reconstruction algorithms
- Investigation of different types of acoustic sensors and sensing methods
- Studies of hybrid (acoustic and optical) detection methods.Acoustic neutrino detection (Calibrator)
• For the acoustic detection of neutrino it is very important to have a good
calibrator in order to:
- Check and monitor the sensitivity.
- Test the system and the reliability.
• Due to the properties of the acoustic neutrino signal (short bipolar pulse
with ‘pancake’ directivity) it is not easy to reproduce it.
ν
CALIBRATOR:Parametric Bipolar Pulse
Hadronic
Cascade Acoustic Sources Cylindrical Propagation
Pancake Directivity ≈ 3º
≈1km
52Acoustic detection neutrinos(Param Ac. Src)
• Parametric acoustic generation is a well known non linear effect first time studied at 60's.
• Parametric acoustic generation consist in a non linear effect that occurs along the sound
wave path when a transducer is fed with a modulated signal with two close frequencies.
• Small fraction of energy is converted
into new spectral components.
• Larger frequencies are rapidly absorbed
in the medium → most interesting
harmonic is the frequency difference.
• It can be used to obtain a low frequency
secondary signal with directivity similar
to the high frequency primary beam.
53Acoustic detection neutrinos (Exp set up)
Emitter hydrophone:10 kHz Free Flooded Ring
- 380 kHz frequency resonance used for our studies
- It is usually used at lower frequencies, so it can be used as
well as a classical transmitter at high frequency
Receiver hydrophone: z axis
x axis
More sensitive below 100 kHz
than for 380 kHz. More sensitive to
the bipolar pulse (hardware
filtering) y axis
Emitter is fixed, whereas the receiver hydrophone scans along x, y
and z axis using a micropositioning system.
• Generador PCI-5412 (National Instruments).
• Amplificador RF ENI 1040L (400W, +55dB, Rochester, NY).
• Digitalizador PCI-5102 (National Instruments)
• Dimension of tank is ∼ 1 m3
54Acoustic detection neutrinos (Results)
Emitted Signal Before Amplification ( Sigma 50 )
• Modulation of signal for emission 0.6
calculated from parametric theory: 0.4
Amplitude [v]
0.2
0
-0.2
-0.4
-0.6
4.8 4.85 4.9 4.95 5 5.05 5.1 5.15 5.2 5.25
-4
Time [s] x 10
• First studies were done using planar 1
Signal 50 Sigma
Primary beam
transduces in order to understand 0.8
Primary beam (Filtered)
Secondary beam (x3)
and control the parametric acoustic 0.6
0.4
generation.
Amplitude [V]
0.2
M.Ardid et al. “Use of parametric acoustic sources to generate
0
neutrino-like signals,” Nucl. Instr. and Meth. A, vol. 604, Jun. 2009, pp.
S208-S211. -0.2
-0.4
• To disentangle the primary and -0.6
secondary beams we applied -0.8
1.3 1.4 1.5 1.6
Time [s]
1.7 1.8 1.9
x 10
2
-4
different filters. Recorded signal and bipolar pulse
Development of a compact acoustic calibrator for ultra-high energy neutrino detection
55Acoustic detection neutrinos (Results)
Emitted signals with different adding time
Emitted signals with different width
between the increasing and decreasing amplitude
(different sigma used) regions
Input Signal (different sigma) Signal 50 Sigma different lengths
1.5
1 500
Sigma 200 100
1 Short
Sigma 100
0.5 Sigma 50
A m p lit u d e [ V ]
0.5
Sigma 25
A m p litud e [V ]
0 0
-0.5
-0.5
-1
-1 -1.5
4.6 4.8 5 5.2 5.4 5.6 4.5 4.7 4.9 5.1 5.3 5.5
Time [s] x 10
-4 Time [S] x 10
-4
• Different emitted signals were studied in order to evaluate the generation control of
bipolar pulse in the medium
M.Ardid et al. “R&D studies for the development of a compact transmitter able to mimic the acoustic signature of a UHE neutrino interaction,”
Nucl. Instr. and Meth. A, doi:10.1016/j.nima.2010.11.139.
56Acoustic detection neutrinos (Results)
• Directivity studies • Shape studies: Control generation of
bipolar pulse
Input Signal (different
Signal 50 Sigma sigma)
11 Primary beam
Primary beam (Filtered)
0.8 Sigma 200
Secondary beam (x3)
0.6
Sigma 100
0.5 Sigma 50
e [V ]
Emitted signals 0.4
Sigma 25
p lit u d [V]
with different width 0.2
A m Amplitude
0
(different sigma used) 0
-0.2
-0.5
-0.4
-0.6
-1
-0.8
1.3 4.6
1.4 4.8
1.5 1.6 5 1.7 5.2
Time [s]
1.8 5.41.9 5.6
2
-4
x 10-4
Time [s] x 10
Signal 50 sigma 500 length
1 Signal 50 Sigma different lengths
1.5 Primary beam
500
0.8 Primary beam (Filtered)
100
Secondary beam (x3)
1
0.6 Short
0.4
0.5
e [V[V] ]
0.2
plitud de
0
AAmmplitu
0
Emitted signals with
different adding time -0.2
-0.5
between the increasing
-0.4
and decreasing -1
amplitude regions -0.6
-0.8
-1.5
1.5
4.5 1.6 1.7
4.7 1.8 1.9
4.9 2 2.15.1 2.2 2.3 5.3 2.4 2.5 5.5
Time[S][s]
Time -4 -4
x 10
x 10
57Acoustic detection neutrinos (Results)
M.Ardid et al. “R&D studies for the development of a compact transmitter able to mimic the acoustic signature of a UHE neutrino
interaction,” Nucl. Instr. and Meth. A, doi:10.1016/j.nima.2010.11.139.
Relationship between the amplitude of the primary and the secondary beam:
58Acoustic detection neutrinos (Results)
Experimental Waveform Experimental Parametric Bipolar Pulse
0.6 0.7 m 0,7 m
0.4
Amplitude [V]
Pressure [Pa]
50
0.2
0 0
-0.2
-50
-0.4
3 3.2 3.4 3.6 3.8 0 2 4 6 8
-4
Time [s] x 10 Time [s] x 10
-5
Analitical Propagation Bipolar Pulse
1 Km
0.04
Reference of pressure
Pressure [Pa]
0.03
0.1 Pa at 1Km
by neutrino of 0.02
10 interaction
0.01
3.2 3.4 3.6 3.8 4 4.2 4.4 4.6 4.8
Time [s] x 10
-4
59Acoustic detection neutrinos (Array)
- Array set up
Rotation
control
Fixing bar
Rotating Array
arm Fixation
Extensible
20 m
60Acoustic detection neutrinos (Conclussions)
It seems clear that the solution proposed based in parametric acoustic sources could be
considered as good candidate to generate the acoustic neutrino-like signals, achieving
the reproduction of both specific characteristics the signal predicted by theory:
- bipolar shape in time
- ‘pancake directivity’.
Complete the characterization of the prototype:
Laboratory
Gandia´s port
Test the behavior of the transmitter using
the Amadeus system.
Future sea campaign (vessel)
In situ integration at neutrino telescope
61Acoustic detection of WIMP’S
Acoustics is not only present in underwater neutrino telescope, can be a
useful tool to detect WIMP’S.
That´s all
Thanks for
your attention
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